remember buying more than 1 tirrre can only be suggested, not required. You are the final decision maker in a case like this. What probably happened is that the tire picked up a foreign object andit bacame a slow leak. You nor anybody else can watch what is going on because your in the car. As you were driving, the tire lost air pressure and built up a very high amount of heat and thus the tire failed to the heat build up from runn9ng low on air presssure. This is not a defect in the tire but rather a road hazsrd. This is also why stores sell road hazard. Remember even if a tire is discintunied, you do not have to buy more than 1 tire if that is all that is required. If they are trying to tell you you need 4 new tires, they are trying to move units and you NEED to find a new place to do business with.